1. Field of the Invention
The present invention relates to a polarized stereoscopic display method and a device thereof, and more particularly, to a polarized stereoscopic display method and a device thereof having a high brightness, by effectively eliminating a polarization filter.
2. Description of the Related Technology
A three-dimensional (3D) display generally refers to technology which adds visual depth information to a two-dimensional image by the use of stereoscopic technology, thereby allowing a viewer to perceive a sense of three dimensions. Over the past 50 years, many 3D display methods have been introduced, and most of them display a stereoscopic image by employing binocular disparity. That is, when right and left images, which are photographed by two cameras, are projected simultaneously, most of the conventional 3D display methods separate the right image from the left image and provide the right and left images to a viewer's right and left eyes, respectively.
The conventional methods for separating a right image from a left image are classified into glasses method (using glasses) and non-glasses method (without using special glasses). The glasses method comprises an anaglyph method, a polarized glass method, and a liquid crystal shutter method. The non-glasses method comprises a lenticular sheet method, a parallax barrier method and an optical plate method. The hologram and the volumetric 3D display methods as dimensional methods are studied. Among the conventional methods, a double polarized glasses method is widely used for stereoscopic movies, stereoscopic monitors, and etc., because it is recognized as the most reliable 3D display method. Lately a large size polarized stereoscopic projection display system, employing two LCD projectors, has been developed.
Conventionally, the polarized stereoscopic projection display system requires linear or circular polarization filters mounted on right and left projectors, so that output beams from the right and left projectors become polarized with being perpendicular each other. However, this lowers the amount of the output beams more than 50%.
Below a configuration of a conventional polarized stereoscopic projection display system will be described by referring to FIG. 1. An object (111) is photographed separately with the same distance apart as that of human eyes using a stereo camera (112). Then two image signals of the stereo camera (112) drive each stereoscopic projector (113), and produce right and right eye image signals and are projected into the projector screen (115) through a polarization filter (114). A viewer sees the image of the projector screen (115) with his right and left eyes separately through polarizing glasses (116) of which right polarization lens is different from left polarization lens, thereby a stereoscopic image is viewed.
The conventional stereoscopic projector (113) produces the right and left images by driving the right and left images inputted from the stereo camera (112) by respective stereoscopic projector systems. The right and left images, which have a perpendicular phase difference through the polarization filter (114) having a perpendicular polarization, are projected to the projector screen (115). That is, the conventional stereoscopic projector 113 is consisted of pairs, such as two lenses, two LCDs driven by image signals and showing the images, thereby embodying respective right and left images and having them perpendicularly polarized through the right and left eye polarization filters (114) and then projecting them on the screen.
FIG. 2 shows the linear polarization filter (114) used in the above conventional projector. The large size stereoscopic projection system using a polarization effect has the linear polarization filters (114), which are oriented at +/−45°, or clockwise and counter-clockwise circular polarization filters placed in front of the right and left projectors respectively. A viewer can sense a three-dimensional effect by wearing polarizing glasses, which allow the viewer to see the right and left eye images separately.
As described above, the conventional polarized stereoscopic projection display system requires the linear or circular polarization filter placed in front of the projector, so that the output beams of the right and left projectors become perpendicularly polarized with each other. This lowers the intensity of the output beam more than 50%.